In recent years, a magnetic flux modulated type magnetic gear, in which a high torque density is realized by using a rare-earth magnet, has been studied and developed (Non-PTL 1). PTL 1 discloses a magnetic gear-type electric rotating machine in which a magnetic gear and a winding type stator are integrated, and more specifically, an improvement of intensity of a permanent magnet field system.
Furthermore, in Non-PTL 2, a configuration in which a permanent magnet is divided in a direction of stack length in a magnetic gear mechanism is disclosed. In Non-PTL 3, a configuration in which an interior permanent magnet is used in a rotor structure of a magnetic gear mechanism is disclosed.